Molecular imprinting is a process for synthesizing polymeric materials that contain highly specific recognition sites for small molecules. The preparation of molecularly imprinted polymers is a process in which host-guest complexes are produced between a template or target molecule (T) and functional monomers (M). Referring to FIG. 1, these host-guest complexes are then fixed by copolymerization with an excess of cross-linking monomer. The template molecule is then removed from the polymer leaving behind voids within the matrix, which are complementary to the template molecule in size, shape and functional group orientation.
Either covalent and/or non-covalent forces such as hydrogen bonding, electrostatic and hydrophobic interactions enable the organization of functional monomers by the template. In addition, the use of metal coordination complexes as the template for polymer bound functionality has also been investigated.
These Molecularly Imprinted Polymers (MIPs) are to a large degree, thermally and chemical stable and have been shown to retain their recognition properties for several years without loss of selectivity or capacity. As a result, they have advantages over more fragile biological systems for molecular recognition and have been referred to as “plastic antibodies.” Under the proper conditions, MIPs have shown the ability to function as selective binding materials capable of enantiomeric separations, micro-reactors, facilitated transport membranes and catalysts. While MIPs have been successful for a variety of applications, little if any regard has been given to surface confinement and miniaturization of these materials. Typically, MIPs are prepared by bulk polymerization that creates a polymer monolith, which is then ground to produce polymer particles. These particles are then used for a variety of applications such as chromatographic stationary phases, selective catalysts or as the recognition elements in chemical sensors.